Forbes contributor Robert Passikoff says Apple has become The Most Valuable Company in the World thanks in large part to chart-topping customer loyalty. "So it’s axiomatic: more consumers behave well toward a brand, a brand sells more, a brand makes more money, its stock goes up," Passikoff writes. And in Apple's case, the stock goes up past $500 a share. So how does Apple do it? Bain & Company 's Fred Reichfeld says it all about loyalty. And, Reichfeld explains in this Harvard Business Review video, other companies would do well to follow Apple's example. It probably won't lead to the same stock valuation, but it might be a path toward sustainable growth: